Statistics students believe that the mean score on a first statistics test is 65. The instructor thinks that the mean score is higher. She samples 10 statistics students and obtains the scores: Grades 96 68.4 85.5 63.9 64.3 61.9 68.4 62.7 73.5 88 Test grades are believed to be normally distributed. Use a significance level of 5%. State the alternative hypothesis: HA:HA: μ>65μ>65 μ≠65μ≠65 μ<65μ<65 Correct State the mean of the sample: Correct State the standard error of the sample means: Incorrect State the test statistic: t=t= State the p-value:
Inverse Normal Distribution
The method used for finding the corresponding z-critical value in a normal distribution using the known probability is said to be an inverse normal distribution. The inverse normal distribution is a continuous probability distribution with a family of two parameters.
Mean, Median, Mode
It is a descriptive summary of a data set. It can be defined by using some of the measures. The central tendencies do not provide information regarding individual data from the dataset. However, they give a summary of the data set. The central tendency or measure of central tendency is a central or typical value for a probability distribution.
Z-Scores
A z-score is a unit of measurement used in statistics to describe the position of a raw score in terms of its distance from the mean, measured with reference to standard deviation from the mean. Z-scores are useful in statistics because they allow comparison between two scores that belong to different normal distributions.
Statistics students believe that the
| Grades | 96 | 68.4 | 85.5 | 63.9 | 64.3 | 61.9 | 68.4 | 62.7 | 73.5 | 88 |
|---|
Test grades are believed to be normally distributed.
Use a significance level of 5%.
- State the alternative hypothesis: HA:HA:
- μ>65μ>65
- μ≠65μ≠65
- μ<65μ<65
- State the mean of the sample: Correct
- State the standard error of the sample means: Incorrect
- State the test statistic: t=t=
- State the p-value:
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